RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 000080001d00c0d0 R11: 0000000000000246 R12: 0000000000000006 R13: 00000000000008d0 R14: 00000000004cb335 R15: 0000000000000000 Unknown ioctl -1071098291 ====================================================== WARNING: possible circular locking dependency detected 4.19.105-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/9738 is trying to acquire lock: 000000007cf4051b (console_owner){-...}, at: console_trylock_spinning kernel/printk/printk.c:1669 [inline] 000000007cf4051b (console_owner){-...}, at: vprintk_emit+0x3d5/0x6d0 kernel/printk/printk.c:1936 but task is already holding lock: 00000000578508f2 (&(&port->lock)->rlock){-.-.}, at: tty_port_close_start.part.0+0x2b/0x570 drivers/tty/tty_port.c:573 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&(&port->lock)->rlock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152 tty_port_tty_get+0x22/0x90 drivers/tty/tty_port.c:288 tty_port_default_wakeup+0x16/0x40 drivers/tty/tty_port.c:47 tty_port_tty_wakeup+0x57/0x70 drivers/tty/tty_port.c:390 uart_write_wakeup+0x46/0x70 drivers/tty/serial/serial_core.c:103 serial8250_tx_chars+0x495/0xaf0 drivers/tty/serial/8250/8250_port.c:1806 serial8250_handle_irq.part.0+0x261/0x2b0 drivers/tty/serial/8250/8250_port.c:1879 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1865 [inline] serial8250_default_handle_irq+0xc0/0x150 drivers/tty/serial/8250/8250_port.c:1895 serial8250_interrupt+0xfc/0x1e0 drivers/tty/serial/8250/8250_core.c:125 __handle_irq_event_percpu+0x144/0x8f0 kernel/irq/handle.c:149 handle_irq_event_percpu+0x74/0x160 kernel/irq/handle.c:189 handle_irq_event+0xa7/0x134 kernel/irq/handle.c:206 handle_edge_irq+0x25e/0x8d0 kernel/irq/chip.c:797 generic_handle_irq_desc include/linux/irqdesc.h:155 [inline] handle_irq+0x39/0x50 arch/x86/kernel/irq_64.c:87 do_IRQ+0x99/0x1d0 arch/x86/kernel/irq.c:246 ret_from_intr+0x0/0x1e arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x95/0xe0 kernel/locking/spinlock.c:184 spin_unlock_irqrestore include/linux/spinlock.h:384 [inline] uart_write+0x3a9/0x6e0 drivers/tty/serial/serial_core.c:612 process_output_block drivers/tty/n_tty.c:593 [inline] n_tty_write+0x3f9/0x1140 drivers/tty/n_tty.c:2331 do_tty_write drivers/tty/tty_io.c:960 [inline] tty_write+0x458/0x7a0 drivers/tty/tty_io.c:1044 redirected_tty_write+0xb2/0xc0 drivers/tty/tty_io.c:1065 __vfs_write+0x114/0x810 fs/read_write.c:485 vfs_write+0x20c/0x560 fs/read_write.c:549 ksys_write+0x14f/0x2d0 fs/read_write.c:599 __do_sys_write fs/read_write.c:611 [inline] __se_sys_write fs/read_write.c:608 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:608 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&port_lock_key){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152 serial8250_console_write+0x7ca/0x9f0 drivers/tty/serial/8250/8250_port.c:3247 univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:590 call_console_drivers kernel/printk/printk.c:1736 [inline] console_unlock+0xbdf/0x10d0 kernel/printk/printk.c:2429 vprintk_emit+0x280/0x6d0 kernel/printk/printk.c:1937 vprintk_default+0x28/0x30 kernel/printk/printk.c:1979 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2012 register_console+0x77f/0xb90 kernel/printk/printk.c:2745 univ8250_console_init+0x3e/0x4b drivers/tty/serial/8250/8250_core.c:685 console_init+0x4f7/0x761 kernel/printk/printk.c:2831 start_kernel+0x59c/0x825 init/main.c:660 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:471 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #0 (console_owner){-...}: lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3903 console_trylock_spinning kernel/printk/printk.c:1690 [inline] vprintk_emit+0x412/0x6d0 kernel/printk/printk.c:1936 vprintk_default+0x28/0x30 kernel/printk/printk.c:1979 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2012 tty_port_close_start.part.0+0x51a/0x570 drivers/tty/tty_port.c:575 tty_port_close_start drivers/tty/tty_port.c:647 [inline] tty_port_close+0x4e/0xf0 drivers/tty/tty_port.c:640 tpk_close+0x8e/0xa4 drivers/char/ttyprintk.c:111 tty_release+0x3ba/0xe90 drivers/tty/tty_io.c:1678 __fput+0x2dd/0x8b0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: console_owner --> &port_lock_key --> &(&port->lock)->rlock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&port->lock)->rlock); lock(&port_lock_key); lock(&(&port->lock)->rlock); lock(console_owner); *** DEADLOCK *** 2 locks held by syz-executor.4/9738: #0: 000000009bd85e75 (&tty->legacy_mutex){+.+.}, at: tty_lock+0x73/0xb0 drivers/tty/tty_mutex.c:19 #1: 00000000578508f2 (&(&port->lock)->rlock){-.-.}, at: tty_port_close_start.part.0+0x2b/0x570 drivers/tty/tty_port.c:573 stack backtrace: CPU: 1 PID: 9738 Comm: syz-executor.4 Not tainted 4.19.105-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1221 check_prev_add kernel/locking/lockdep.c:1861 [inline] check_prevs_add kernel/locking/lockdep.c:1974 [inline] validate_chain kernel/locking/lockdep.c:2415 [inline] __lock_acquire+0x2e19/0x49c0 kernel/locking/lockdep.c:3411 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3903 console_trylock_spinning kernel/printk/printk.c:1690 [inline] vprintk_emit+0x412/0x6d0 kernel/printk/printk.c:1936 vprintk_default+0x28/0x30 kernel/printk/printk.c:1979 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2012 tty_port_close_start.part.0+0x51a/0x570 drivers/tty/tty_port.c:575 tty_port_close_start drivers/tty/tty_port.c:647 [inline] tty_port_close+0x4e/0xf0 drivers/tty/tty_port.c:640 tpk_close+0x8e/0xa4 drivers/char/ttyprintk.c:111 tty_release+0x3ba/0xe90 drivers/tty/tty_io.c:1678 __fput+0x2dd/0x8b0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x415fe1 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fff967d5d20 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000415fe1 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000770270 R09: 01ffffffffffffff R10: 00007fff967d5df0 R11: 0000000000000293 R12: 000000000076bf20 R13: 0000000000770278 R14: 0000000000000000 R15: 000000000076bf2c SELinux: unrecognized netlink message: protocol=0 nlmsg_type=1969 sclass=netlink_route_socket pig=9752 comm=syz-executor.0 IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready CPU: 1 PID: 9758 Comm: syz-executor.2 Not tainted 4.19.105-syzkaller #0 overlayfs: conflicting lowerdir path Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0xa/0x1b lib/fault-inject.c:149 __should_failslab+0x121/0x190 mm/failslab.c:32 should_failslab+0x9/0x14 mm/slab_common.c:1558 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] __do_kmalloc mm/slab.c:3725 [inline] __kmalloc+0x2e2/0x750 mm/slab.c:3736 kmalloc_array include/linux/slab.h:637 [inline] kcalloc include/linux/slab.h:648 [inline] alloc_pipe_info+0x19c/0x430 fs/pipe.c:664 splice_direct_to_actor+0x76c/0x970 fs/splice.c:921 do_splice_direct+0x1da/0x2a0 fs/splice.c:1068 do_sendfile+0x597/0xce0 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64 fs/read_write.c:1494 [inline] __x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1494 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c449 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa4c17f6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fa4c17f76d4 RCX: 000000000045c449 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 000080001d00c0d0 R11: 0000000000000246 R12: 0000000000000006 R13: 00000000000008d0 R14: 00000000004cb335 R15: 0000000000000001 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready SELinux: unrecognized netlink message: protocol=0 nlmsg_type=1969 sclass=netlink_route_socket pig=9801 comm=syz-executor.0 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready SELinux: unrecognized netlink message: protocol=0 nlmsg_type=1969 sclass=netlink_route_socket pig=9848 comm=syz-executor.0 IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready ttyprintk ttyprintk: tty_port_close_start: tty->count = 1 port count = 2 capability: warning: `syz-executor.2' uses 32-bit capabilities (legacy support in use) audit: type=1400 audit(1582268039.030:55): avc: denied { ioctl } for pid=10053 comm="syz-executor.2" path="socket:[37755]" dev="sockfs" ino=37755 ioctlcmd=0x8980 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 base_sock_release(0000000061815ed4) sk=000000001665c7fb base_sock_release(0000000031ea7d61) sk=00000000596d00fb IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready SELinux: unrecognized netlink message: protocol=0 nlmsg_type=1969 sclass=netlink_route_socket pig=10353 comm=syz-executor.1 IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready